Howarth has said his client didn't know at the time of his arrest that pressure cookers were used in the Boston Marathon attack and was bringing the pressure cooker for use by his nephew, a student at the University of Toledo in Ohio.

U.S. Justice Department lawyers did not immediately return an email from The Associated Press asking if they oppose Al Khawahir's release request. U.S. Customs and Border Protection also has a detention order for him, and he would need to clear it as well to gain release.

Howarth used the motion to challenge the government's case, saying that Al Khawahir carried a valid, current Saudi passport as well as an expired passport, "purportedly altered," that contained a visa stamp for his entry to the U.S.

Howarth said the difference between two explanations that Al Khawahir gave federal agents about why he was bringing the pressure cooker -- that his nephew couldn't find one in the U.S. and that the ones available here were defective -- were "possibly a distinction without much difference."

He said Al Khawahir "represents neither a risk of flight nor a danger to a person or the community."

Al Khawahir's next scheduled court date is May 28 for a hearing on whether there's enough evidence for the case to proceed.

In his motion, Howarth said his client contacted his nation's diplomats immediately after the arrest, and the government of Saudi Arabia "pledged its support" of him.